Good afternoon, my name is David and I will be your conference operator today. At this time, I would like to welcome everyone to the Fastly Fourth Quarter 2020 Earnings Conference Call. All lines have been placed on mute to prevent any background noise. After the speakers' remarks, there will be a question-and-answer session. [Operator Instructions] Thank you. I would now like to turn the conference over to Maria Lukens, Vice President of Investor Relations. Please go ahead.

Hi everyone, thank you for joining our fourth quarter and full year 2020 earnings call. We have Fastly CEO, Joshua Bixby and CFO, Adriel Lares with us today. Before we start, I want to remind everybody about the usual format of our call. We published a shareholder letter on our investor relations website and with the SEC about an hour ago. Since the letter provides a lot of details, we'll make some brief opening remarks and reserve the rest of the time for your questions. During this call, we will be making forward-looking statements, including statements related to the expected performance of our business, future financial results, the integration of Signal Sciences strategy, launch and growth and overall future prospects. These statements are subject to known and unknown risks, uncertainties and assumptions that could cause actual results to differ materially from those projected or implied during the call. Please take a look at our filings with the SEC and our Q4 2020 shareholder letter for a discussion of the factors that could cause our end results to differ. Also, note that the forward-looking statements on this call are based on information available to us as of today's date. We disclaim any obligations to update any forward-looking statements except as required by law. Also during the call, we will discuss certain non-GAAP financial measures. Reconciliations to the most directly comparable GAAP financial measures are provided in the shareholder letter on our investor relations website. These non-GAAP measures are not intended to be a substitute for our GAAP results. Finally, this call is being webcast and will be archived on our website shortly afterwards. With that, I'll turn the call over to Joshua.

Thanks, Maria. Hi everyone and thanks for joining us today. We had a busy and successful quarter and it’s reflected in our results. We delivered 40% year-over-year top line growth with revenue of nearly $83 million. Last year, our world changed and businesses changed with it. We saw many companies invest more heavily in their digital presence than ever before. Subsequently, we’ve added new customers while our existing customer base grew. These customers include Blackboard, a top tier learning management system. UC Davis, a higher education institution, an enterprise tech company and one of the world’s largest telecommunication companies among others. We’re also being tractioned in the rapidly growing gaming vertical and one new and additional business with two leading gaming companies. We’ve also seen our customers go above and beyond to help their communities during these challenging times. Two stories that encourage me are from Gannett and Doximity. Gannett, a leading media and publishing company launched support local, which allows people to support their neighbourhood businesses through gift cards as well as take action which provides resources to those looking to step up when it comes to social and racial justice. We’re proud to have supported them in getting these sites up in running in a matter of days. Doximity, a company that helps medical professionals virtually connect to patients saw double digit user growth and a 30 times increase in traffic on their secure calling feature within just a few weeks with the onset of the pandemic. They turned to our security offerings, which gave them the control they needed to block malicious traffic, all while providing reliable connectivity to patients at a time when it was needed the most. Our other customers delivered breaking news during the crucial election brought people together through virtual gatherings, helped entertain…

Thank you, Joshua. And thank you everyone for joining us today. We rounded up the year with another strong quarter driven by robust customer demand, particularly from both new and existing enterprises that are continuing to integrate Fastly’s modern edge platform into their systems. As I go through the numbers, I want to point out as we noted in the shareholder letter, that the contribution of Signal Sciences following our acquisition has been consolidated into our fourth quarter financial information. So the revenue and margin numbers I'm about to get include Signal Sciences. However, we have not yet included Signal Sciences in most of our key metrics this quarter, and intend to report consolidated metrics later than 2021. In order to see the incremental contribution on customer growth from Signal Sciences, we have provided their total customer counts and number of enterprise customers, as of Q4 2020. This quarter, we generated $83 million in revenue, net of the $2 million deferred revenue write down related to purchase accounting adjustments from Signal Sciences acquisition, representing 40% year-over-year growth. For the full year 2020, we generated $291 million in revenue up 45% year-over-year. We're continuing to drive leverage in the business. GAAP gross margin is 59.2% for the quarter, up from 56.7% in the same quarter a year ago, and 58.7% for the full year up from 55.9% for 2019. Non-GAAP gross margin, which excludes stock based compensation and amortization of acquired intangible assets was 63.7% for the quarter, compared to 57.6% in the same quarter last year. Full year non-GAAP gross margin was 60.9% compared to 56.6% for 2019. While our gross margin will continue to be impacted by the timing of personnel and infrastructure related investments, as well as seasonal usage by customers on our platform, we remain confident in…

[Operator Instructions] Your first question comes from the line of Jonathan Ho with William Blair. Your line is open.

Hi, congratulations on the strong quarter. I just wanted to start out with maybe your guidance on the CapEx side of things. And just, trying to understand, why you have, sort of the confidence level to sustain at a higher level, you're just given some of the headwinds that you're facing from a capacity standpoint, from that large customer last year, as well as in may be some tough, tougher COVID comparisons.

Oh, sorry, it’s Joshua. Jonathan, are you saying why is that number not higher or lower? I just wanted to understand the crux of the claim.

Oh, and so in terms of sustaining, bonds at 10%, sort of long term target, what's giving you the confidence to keep that number higher?

Oh, I see got it. Yes, I mean, I think where that's really coming from is just the makeup of the customers that we have brought on board, some of the guidance that they're giving us with respect to what they're trying to do what we're seeing in the customers themselves. And, as you, as you've heard from me in the past, the CapEx as a percentage of revenue that we have today, is still meaningfully lower than is exceeding some legacy providers that already exist out there. And in our long term model, we think we can get to 10%, while still growing relatively quickly. So we're in some respects, keeping in mind what we've seen so far, particularly in Q4, but also some of the Signals that our customers that are currently telling us today, which is built into our guidance.

Got it. And then, just in terms of a follow up, can you give us a little bit of an update on your large customer and maybe what your expectations at this point are in terms of either headwind for 2021, or contribution from that customer? Thank you.

Yes. Hey, Jonathan is Joshua here. Appreciate the question. As we've talked about throughout this process, they remain an important customer to us. They continue to rely on us for important workloads, and that hasn't changed. As you know it peaked above 10% for a short period at the start of the pandemic, but we have a number of large customers and a handful, who may come in and out of that 10% category as they grow. As you know, when your services are software based, global and infinitely scalable, on the Edge, and you're dealing with customers who are growing at unprecedented rates on a usage based model, you're going to have variations over time. These customers, as you know, rely on us for performance, security, reliability, and we're really proud to continue to be the solution that they trust. So we have modeled in to our guidance, the relationship with a strong relationship, we've modeled in exactly what we've heard from that customer. And, that's modeled into our guidance. So we feel optimistic.

Great, thank you.

Thank you.

Your next question comes from the line of Robert Majek with Raymond James. Your line is open.

Great, great thanks. Just wondering if you can give us any more color on Signal Sciences revenue contribution in the quarter, and what's baked into your guide for next year? And then on the expansion metrics, understand that you'll give us update numbers that includes Signal Sciences later in the quarter. But can we just say that Signal Sciences would have added to the net expansion rate?

Adriel, do you want to go those two?

Sure. I'll also take the second part of your question. First, it's more likely later in the year. The challenge for us in Signal Sciences is subscription based products. And we're still working through how we want to continue to offer that as well as the same time continue to offer the usage based model that our Fastly’s historical customers have been used to. So I think it's going to take us a little bit of time to sort of make sure we are thoughtful about how we report those metrics together, especially as they begin to contribute together, as we have so far. Related to what the contribution was for Signal Sciences in Q4. I think you recall, when we started the quarter, we had about an $8 million deferred revenue. There was a -- that we had that we thought we would recognize, over Q4, we took about a $2 million deferred haircut related to the purchase price acquisition related to that. So that should give you some sense of kind of where we ended up. And as for the year, we're modeling, and clearly what we've seen from a growth standpoint that we've seen historically, and especially as well as in Q4, and you're trying to build in, guidance into the current guidance today. It's a little bit difficult to kind of ascertain how much level exactly be from Signal Sciences, partially because we're already beginning to sell in abundant fashion with them. So historically that's very similar to what we've done before.

Great, thanks. And maybe just one more from me, voice chat rooms like clubhouse and Twitter spaces have been getting a lot of attention lately. It's widely speculated that Agora serves the traffic for Clubhouse. I'm just wondering if this vertical is a potential opportunity for Computed Edge, just given how latency sensitive this traffic is.

Yes, it's Joshua here. Robert, I think that's a -- we're seeing we're seeing really interesting opportunities in all of these, latency sensitive environments. I'd call your attention to what we talked about in the opening and what we talked about in the letter around gaming, right, which, for the high value games, latency is critical. One of the reasons that we're making really strong inroads in that vertical is because of our performance, the reliability that performs. But also, as you mentioned, what Edge Compute can bring to the table here. So I would say, I can't speak specifically about any customers. But I would say I think the advent of this as a medium is good for our business and good for computing.

Thanks a lot. I appreciate the call.

Thank you.

Your next question comes from the line of Tim Horan with Oppenheimer. Your line is open.

Thanks, guys. Can you give us at a high level maybe a sense of how bookings and just how customer interest has been maybe in the second half of this year versus last year, just given the COVID impacts? And secondly, can you maybe just give us a little more color around revenue? Maybe what percentage of revenue is kind of tied to application delivery or making the buyings versus subscription at this point? I know things are moving around a lot. Thank you.

Sure, let me let me start on the first on the first question. I think that, overall the revenue that the revenue that we have continues to grow, as you saw in the quarter, and I think that continues to stay in that in that same range. We've talked in the past about half of our revenue is committed that that remains the same half of it as usage. When you look at the bookings and customer interest in the second half of the year versus last year, we're really happy and excited. And I talked about this in the opening remarks about the strength that we saw in the security side of the business that continues to build on itself, the pipeline continues to build. We’re also starting to see a lot of interest in the compute capabilities that the business brings to the table. And we, I've been personally talking to customers were the security of our compute the scale of our compute the performance of our compute, those three factors are really, really important in purchasing decisions. There are a lot of cross sell opportunities that we're bringing, as we start bringing these multiple products to the table. And given that we're a cloud on ramp to the three major clouds, and we sell a full suite of transport security, computed edge products and other services, we continue to see that grow. So really confident and optimistic in terms of how we sell that. Adriel I’ll turn it to you in terms of percentage of revenue.

Sure. Thanks, Joshua. So Tim, I think, if you're purely thinking Signal Sciences because you do have security revenue outside of that, but if you're just thinking Signal Sciences, it was it was less than 10% in Q4, primarily, just from the standpoint if you take for the top level number, the amount of defer that we were going into and what would actually got recognized that $2 million. So it's sub 10%. Today, it's clearly growing quickly. And again, which we're selling together with Signal Sciences. So it's going to be a little bit more difficult as we continue to sort of March 2021 separates the two, but at least it gives you a good sense of sort of where we're starting from.

Your next question comes from the line of Rishi Jaluria with D.A. Davidson. Your line is open.

Hey, guys thank you so much for taking my questions and nice to see continued strong results. Wanted to first ask about the net retention in the quarter, if we look, at NRR, even if we're on a trailing 12 month basis. It did decline sequentially from Q3. Was wondering if you just give us a little bit more color on how we're -- what's going on in that metric, is that driven just by fewer expansions. And maybe we've historically seen as I have the large customer that we've talked about on the call disproportion responsible for that any color would be helpful. And then I've got a follow up?

Sure, Adriel, you want to take a first crack at that?

Certainly, hey, Rishi. So recall that the NRR takes the end of the month. And in particular last year, sort of our denominator, if it impacts that number for Q4, we did have a decent sized, live event that was nice, and it's good for the for the ending quarter of Q4, 2019. But it did impact that particular month. So that's why you sort of see a decline. It wasn't necessarily related directly to sort of a [Indiscernible] largest customer. However, two points I'd like to make, in addition to that, if you look at the LTM, and our version, which we also published, which is 156.5% that still showed good strength over 2020 over 2019. But as we move further into 2021, there will be some instances if we have, especially as we move into Q2, Q2 was a particularly strong growth, particularly related to COVID. So you may see some impacts in that quarter in NRR and DBNER, but I just want to sort of give you some sense of some of the impacts that you may see, but at least for Q4, there's nothing there that I saw as sort of negative or much more optimistically, especially when you consider the LTM version of that.

That, that's helpful. And then Joshua, you highlighted both on the prepared remarks and in the shareholder letter, some of the strength that you saw in gaming. I believe, historically, this hasn't been a huge vertical for you, but clearly seem to be getting a lot of real traction there. How are you thinking about the gaming opportunity, long term, and maybe what's changed that it's made it a more attractive and presumably less commoditized opportunity than, maybe it historically has been? Thanks.

Yes. Rishi, great question. I think, this market, it has two sides to it, right, as the media market does, which is there is a commodity side, and Fastly spends our time energy, certainly on the value side. I think what's changed is two things. The first is beaming companies are realizing that the performance, and particularly the low latency aspect of performance just is more and more important than it ever was. And so there's an element there, where as you are trying to drive latency out reliability up, you start looking around the market, and as you know, there not a lot of options to do that at, at scale and at a global scale. So that that's one element. I think the other element that's really interesting is the opportunities for compute in this market where traditionally we have seen this market do a lot at the server side and in a lot of markets, this one included, people now are seeing this incredible opportunity to bring Logic and Compute to the Edge. And that's sparking a real transformation. And imagine a Tory [Ph] process for people like what if? And what if, I mentioned it, but I, I saw a multiplayer version of Doom, all running on Compute at the Edge. And when you when you look at those types of use cases, it really transforms how gaming can work in the future. And gaming companies are always reaching for the future. I mean they often are the trailblazers in this area. So I think there's a trailblazing element which is grabbed attention through compute. And there's also this need for low latency and high performance, which just continues to ramp up. Those are two reasons that that we're certainly seeing, and I'm seeing in the discussions I'm having, that’s exciting.

Right, that’s really helpful. Thank you so much, guys.

Thank you.

Your next question comes from the line of Jeff Van Rhee with Craig-Hallum. Your line is open.

Great, thanks. A couple quick questions. First, I guess, Adriel as it relates to 2021. If I looked at the non-GAAP operating loss, it looks like there's what maybe, I don't know 20 million or so more spending there relative to where the street was. Just curious if you break that down by line out of where you think that's going to fall. What exactly are you spending more on just a little color there would be helpful. And then congrats on the hire. Obviously, Brett joining the team brings a lot of skills, just curious, any previews in terms of additional areas of focus out of the gate, things that might change here?

Sure, Adriel why don’t you go on this one. And I'll go take the Brett question after.

Sounds good. Yes primarily, the driver for the spin. If you look at our Q4 non-GAAP operating burn, it basically gives you a bit of a preview with our expanded acquisition, and the expenses brought on with the Signal Sciences team, it's really sort of acceleration, the investment into that, but it's really driving where we are in 2021. And another way to sort of put this in perspective, as well as a non-GAAP operating loss in 2019 with what 9% [ph] or 17% [ph]. If you look at the year 2020, it was minus sort of nearly 6%, about 5.8%. So there's a little bit of we kind of got a little further ahead and sort of share your preview at scale that business can look like, but we still want to invest in, you're still on a path to eventually get to profitability. And I think 2021 is still within that path. But in terms of sort of how it breaks down, I don't know that the category is going to look all that different than where historically, we want to spend certainly more into brand and marketing to go after the security cameras or people going after as well as computer. So if we've got some spending in there. The R&D effort that with the engineers and production, Signal Sciences and certainly an additional investment we want to push into. And I think, G&A is an area where we do want to get some leverage, it's going to take us a little bit longer. In 2020, we want to make some investments there so that we can continue to scale that area, but right now, a couple of which our ultimate path. And again, Q4 with a good sort of preview to the launching pad for 2021.

Yes, and on and on Brett. I mean, I'm thrilled about that announcement, as you know, this has been a process for us to really get the right person. And in terms of focus areas, we we see just a tremendous opportunity on the security lead story arc here. I've started to talk to customers who are not only using us for their web and API security, but certain of their IT applications and IT workloads. I think that's a really interesting area of expansion for us. If you think about us being the on ramp to the three major clouds and a full suite of transport, security compute features, there's still a lot to do in terms of getting out there and having that message be heard. So, a really strong focus on landing new customers, a continued focus on ensuring that the customer experience that we have and that's highlighted by 99% revenue retention rate, which is tremendous. That we keep that as we grow. So, as Adriel said, we're going to continue to invest here. We are just over the moon with the Signal Sciences team. And feel so thrilled that they here. There's still work to do in terms of integrating them. But I'm really excited about the security lead side. And then when we look at the compute side of our business that really allows us to democratize some of our work. So where can we attract more developers at scale? And I think those are two areas that he's definitely going to be focused on.

Great. Very helpful. Thanks.

Thank you.

Your next question comes from the line of Brad Zelnick with Credit Suisse. Your line is open.

Great. Thanks. This is Ray McDonough on for Brad. Maybe one for Joshua to start. In the shareholder letter, you briefly mentioned that you've developed methods to leverage the platform to deliver streaming traffic in more scalable and profitable way. Can you provide some color on what those methods entail? How that might impact if at all the type of traffic you're willing to take on? If that changes the way you think about the price points of which you're willing to take on various types of traffic?

Yes, Ray. It's a great question. I'm really proud of the work that we're doing there. So we talked about a few components of that, Precision Path is one of them. So we have since the start of Fastly, we've been asking ourselves the question. How can we deploy the most efficiently? How can we get the most value out of our network, out of the bandwidth that we have? And how can we bring these sort of self-healing capabilities into our network so that we can do this efficiently? If you look at the number of pops, the number of servers, the number of people we have, efficiency and optimization has always been front and center. So, I think the answer is, we are looking to continue to spend our time and our energy focusing on the high value side of this market. When you bring value and that's demonstrated by the gross margin leverage that we demonstrated in Q4 with the growth, there's a lot of high value business out there. And as I talked about earlier in the gaming sector, more and more people are realizing that performance really matters. And this is a process that is going to take -- it's going to continue to take hold. But we're really seeing that 2020 was a year where that became really, really in focus. So I would say, examples of that would be Precision path, we talked about our support, quick, all of this is about better, faster, more reliable. And then we're constantly looking at efficiency. I mean, from the first days that the business started, how can we get the most out of our hardware. So I don't think it changes our focus. It doesn't change the types of customers where we go after. It really doesn't focus on sort of opening up the bottom end of this market, or the low value side of this market. We're going to continue focused exactly where we are. And as Adriel said, we'll continue to show gross margin leverage towards our midterm model of 70% gross margin, and we're making traction in that regard.

That's helpful. And if I could maybe a follow-up for Adriel, and just to build on Roberts question around guidance and what's included from a Signal Sciences perspective. Is it fair to grow what seems like a $6 million contribution this quarter to something where we get to something like $30 million or $40 million in organic contribution from Signal Sciences in 2021. And maybe you can kind of comment on that gross margin impact. Should we expect incremental expansion on the core Fastly business, as we think about 2021 and layering in Signal Sciences?

Yes. I would think about it just given that just clearly in year. And as you recall last year when I gave guidance for 2020, clearly, really idea of work sort of coming up for all of us. But that kind of guided at sort of 30-ish percent annual range for growth. And I think I'm trying to take a similar tech this year for the overall business. And that's actually including Signal Sciences. So, they were growing clearly quite fast when the acquisition was first announced. And I think for now, just given that it's clearly, we are trying to emphasize the cross-sell possibilities. I would sort of stick at least for now at a high level just kind of incorporate in together with us. And then as we get a little bit further in to the year we can give a little more perspective in terms of what we've seen this last quarter was great in terms of just the initial indications about our ability to sell together with Signal Sciences. But we're now sort of one team. And I think at least for guidance side, I sort of keep to where we are today.

Okay, great. And any thoughts on just core Fastly margins and expansion there?

Yes. I think from a sort of core margins standpoint, there's certainly, as Joshua just pointed out, there's reasons for optimism. And at this point, when I think about it from an overall gross margin standpoint of 2021, I still feel good about adding somewhere 100 bps and more. But again, I want to sort of see the next for us what really matters? What's the mix both in the type of traffic we have, and that we have Signal Sciences, which will be incremental to that and additive to that. And I want to see how the mix of them growing with us and can possibly accelerate that. But we have a little bit more time as we get further into the year.

Make sense. Thanks for the color. Appreciate it.

Thanks Ray.

Your next question comes from the line of Will Power with Baird. Your line is open.

Hey. This is Charlie Erlikh on for Will. Thanks for taking the question. I was hopping to ask you a question about guidance. Maybe just what's contemplated in the revenue guide in terms of the macro environment and COVID-19 in terms of opening up and potentially starting to work from the office and whatnot. But you can maybe talk about some of the assumptions you're making in the 2021 guidance in terms of those factors?

Sure. Adriel, why don't you start?

Sure. So, I mean, it kind of based on an answer previously that I gave. I think we're be conservative just in terms of what the -- how much visibility we can see at this point. Certainly, we've got a bit more visibility into Q1 in terms of what we've seen so far. In terms of sort of the macro perspective, I think we do see -- we certainly taking note of what folks have chose some other Legacy CDN. We noted about their assumptions in the world. I think vaccines are rolling out. So, I think we hope for -- I personally hope for sort of normalized year. And I think for now, we're not assuming anything faster than that at this point. So I think that's why we kind of see the guidance numbers are what they are. But again, as we get little further into the year, we'll have a little bit more sense of kind of what world are we going into. And how much of that faster we'll see our growth rate than what we original thought.

Okay. That's make sense. And is there any way to maybe think about potential contribution from Compute@Edge in 2021 revenue. Or is it just mainly ramping in 2021 and then seeing more meaningful impact in 2022. How should we think about the contribution from that?

Yes. My prospect on that is that we also ease from my prospective also thinking about this will pay year to learn. In 2021 we certainly got some earlier learning so far from some other customers. So -- and it could some meaningful contribution. But they would be in latter half of the year. And again, I think -- I'm thinking about 2021 must more of just learning what are the use cases? What are data calls that we can use to learn as we're lean in to 2022 and beyond [Indiscernible]

Make sense. Thanks, Adriel.

Thanks, Charlie.

Your next question comes from the line of James Fish with Piper Sandler. Your line is open.

Hey, guys. First, our understanding there are few larger media renewals often in Q4 and actually for the first half of the year. How have you and are you approaching those renewals? And specifically, what are you guys seeing around pricing, given a lot of noise out there?

Yes. It's Joshua here. I think that, we have renewals all the way through the year, including in Q4. What you see in Q4, obviously with the increase in gross margin, and the increase in usages. And we feel confident about what we saw in the past. I think when we look forward, as we talked about our innovations continue to drive value. There is a commoditized delivery business in the market. We have stayed away from that. I think that's proven to be a prudent choice. And we continue to look for customers who care deeply about the performance of their content, who care about the security of their content and want it to be reliable. So we -- and we've always taken a balanced approach here. I don't think that that's going to change going forward. We simply don't do deals that we think are bad for the business and premium content we think. Demands that performance and reliability. So nothing in the future that would be unusual in that regard. And we continue to remain optimistic.

Got it. Understood. And then obviously, Brett comes from a good background at Rubrik. I guess what made you guys pick Brett? Is it more his background on sort of the storage and security side as you start to think about Edge compute and Edge Services? Or is it more like the enterprise experience or something else?

Yes. It's really a combination of all of that. Plus, I mean, if you think about the VMware experience. If you think about the security experience and the Rubrik experience, what you get is? You get that enterprise. You understand security infrastructure. You understand compute. You've seen fast charging growth startups. You've seen around the corner to billions of revenue. All of that was really valuable to us. So I think we understand as we grow, that we need to continue to invest and optimize, that's certainly going to be a theme for 2021. And he's the right leader for that. So really, it's combination of all of those plus. Very excited about that.

Thanks, Joshua.

Thank you.

[Operator Instructions] Your next question comes from the line of Walter Pritchard with Citi. Your line is open.

Hey. Thanks. Just want to make sure we're totally clear here on this Signal Sciences contributions. So you had modeled $8 million coming off the balance sheet and it ended up in $6 million because of the write down rate. As you go into Q1, is it fair to say that you have that sort of $6 million rolling off as well at that rate? And then I think that probably doesn't include kind have new business that you're signing -- that either the Signal Sciences is doing on their own? Or you're doing on a bundled basis? I'm just trying to get a sense as to the balance sheet piece, and then the new business that would roll into Q1 and then as we proceed throughout the year?

Hey, Walter, it's Adriel. You got that methodology correct. As anything book post, October 1, since the acquisition has no purchase cost accounting adjustments that you get clearly for revenue credit moving forward. So from our standpoint, it really matters how successful are we together in sort of bringing number of new bookings together. So that's a good methodology, or at least a good way to think about it.

And so then, as we think about Q4, the contribution to revenue, I mean, the six plus there was another piece there, and then Q1. Is there any way you could help us understand kind of what that total picture is? Because I think that's really the piece that people are going to try to get to understand the underlying growth rate of the Fastly pretty Signal Sciences?

Yes. And I think that's the part where it begins to meld in with some of the combination selling that we do together. So I've tried to give you just a ballpark in general. And your methodology is probably ballpark correct. And I think as we move into Q1 and Q2 of this year, those are going to begin to blend together. And so it's not going to be distinctively Signal Sciences, or distinctively Fastly, they're going to be sold together. many of our customers buy delivery and security. They want to sort of secured with it to sort of do that [Indiscernible]. And so little buy sort of one blended rate. So from our standpoint, we're beginning -- I want to give you sort of a starting point to which direction to go. But at least as we begin to move forward we're not break those out at this time.

And then just on headcount, I think somebody asked earlier on the spending. Any sense as to where headcount may in the year just we can sort of understand kind of that picture in totality, understanding there's a Signal Sciences be flaring in your organic growth as well?

Yes. We added about -- in Q4, we added about 150 folks from the Signal Sciences team. I'd say, given where we ended the year at about 939. We're going to certainly add a number of folks. I don't think we're going to add them at the sort of the same clip we did in Q4, I quoted, that was a nice bump, and we're probably going to ameliorate that. But given that the leverage, or sort of the operating burn, that we just experienced in Q4 is more indicative for the year. We'll probably grow the rates more similarly. Although the idea is that by the end of 2021, we're going to sort of reassess where we at that point, how fast are we going, what are we getting for those -- for that investment in headcount. And if we continue to see great returns on them, then we'll sort of reconsider where we are at that point. But at least hopefully that gives you some sense of kind of how we're thinking about the year.

Great. Thanks, Adriel. Okay. Thank you.

Thanks Walter.

Your next question comes from the line of Tal Liani with Bank of America. Your line is open.

Hi, guys. I wanted to ask about the core growth that lot of people already asked. And I'm trying to understand the -- if you can quantify the impact of COVID. And I don't know if it's possible at all. But I look at your revenues last year, 4Q was -- I'm generalizing, 4Q was 61. 1Q was 63. And then it jumps to 75 and 71. And there was also TikTok in the mix. And I'm trying to understand if you saw an increase in post COVID, post work from home, which would be natural for your kind of business. And if that's the case, wouldn't the growth rates decline this year just because of the tougher comps? So I don't know if you can quantify for us a little bit of the TikTok contribution kind of throughout the year or something or talk about it just qualitatively? Thanks.

Yes. Tal, its a great question. Obviously, it's hard to look into crystal ball for next year. I think what we've seen is a few phenomenon. The first is that every industry is different. But we're seeing more people use the internet. You've seen that and we've seen it in behavior and habits have changed. So I think the first element of this is we believe that there are sustainable changes that have happened to the digital transformers. They will maintain additional market share and continue to grow. And is there a new normal? We don't know. We're trying to be conservative in how we look at it. But we certainly look at the future optimistically. We believe that those who are digitally transforming are taking a outside share of market and that outside share continues to grow. So that's one element. I think the other element it's important here and we've been talking about it. It's just the role that security plays here. As we continue to innovate, bring fast and reliable digital experiences to all people around the world, what we're seeing is additional threats, right? So naturally, these threats and security needs follow the traffic. And what we're seeing is that it takes a totally different tool to fight against these attackers. Attackers are developers too. They're not bogged down with the limits of legacy solutions. They're nimble. They're using modern tools, modern workflows, they're digitally transforming, too. And so there's two elements here, which are driving our optimistic view of the future. The first is this digital transformation and additional market share. The other element of this, its important is around security and what we're seeing there. So we, as Adriel said, we're guiding conservatively. And we think that that's prudent. And we're seeing these tailwinds that we're really enthusiastic about. So I don't know if that totally answers your question. But that's how we're looking at it right now.

Can I have a follow up. Last quarter, there were questions about it throughout the quarter. And maybe you can speak about, and again, I don't know how much you can share with us. But the more you share is, the better. You can share with us kind of the role of TikTok, or your role in the network of TikTok meaning, is the traffic gone completely? Or are there types of traffic that they can remove and types of traffic that can -- that has to stay on your network? So can you talk about your role in the service of a company like TikTok and again, specific to..?

Sure. Yes. And they remain an important customer. They continue to rely on us for important workloads. As you know, they peaked above 10% for a short period at the start of the pandemic. But we have a large number of large customers and a handful, as I said, who may come in and out of this 10% category as we grow and as they grow. So, ultimately, we have strong relationship, we continue to be very close to them. We've modeled in what we see for the year. But we have in the quarter and over the last few months continue to diversify and get more large enterprise customers. There may be more 10% customers in the future. But our model is really built on a handful of ease and continued growth. So I think as an enterprise business that that is part of -- that's part of our growth.

I'll take it offline, because I'm trying to understand what kind of -- when they go down what kind of services they have to keep on your network because you provide something unique. They cannot find anywhere else then what kind of traffic they can remove out of your network, because it's more of the commodity part. So we can take it offline to discuss it.

Thanks, Tal. Appreciate it.

There are no further questions at this time. Mr. Bixby, I turn the call back over to you for closing remarks.

Before we sign off, I want to thank our employees, customers, partners and investors. I'm extremely proud of all that our team has accomplished in a year filled with such uniquely challenging circumstances and unexpected road bumps. And we're humbled to be both a witness and enabler for how we've supported our customers, many of them thriving, even under incredibly difficult circumstances. I look forward to seeing what lies ahead for all of us this year, and I hope to connect with many of you at the upcoming Morgan Stanley TMT Conference. Thank you.

This concludes today's conference call. You may now disconnect.