Senior Full Stack Engineer

What is TheirStack?

Our product & customers

TheirStack is a job and technographic database that helps companies find clients. We scrape jobs and company information from the internet in almost real-time and let our users consume it in a structured, straight-forward way.

We scrape about 400k jobs every day, receive ~1M requests/day, have hundreds of paying customers and thousands of monthly active users.

Our data is leveraged by customers from different verticals, such as:

• B2B SaaS companies like Superflex.ai (a tool that generates code from Figma files), pull with our UI lists of companies utilizing a technology (Figma in their case) to drive their cold email outreach.
• Job boards like EnergyHire - the largest energy-sector recruiting agency - use our Jobs API to backfill their job board with all jobs publish on Linkedin, Indeed, Glassdoor, Workable…
• Salestech companies like Databar.ai use our Technographics API and Jobs API to provide jobs and technology usage data so that their users can power their outbound campaings with it
• Security companies use our full datasets of 70M jobs and the full tech stack of 5M companies to identify third party risks

Our company - philosophy

We haven’t raised any money and don’t have plans to do so.

Our goal is to keep building a sustainable, profitable company. Small in headcount and big in revenue per employee.

Success for us means living a good life solving intellectually stimulating problems and building a good product that ‘sells itself’.

We’re a company founded and driven by engineers, focused on creating exceptional solutions. Our focus is on building a product that speaks for itself, without relying heavily on traditional sales efforts. Every decision we make is guided by the question: 'Can this be discovered, used, and purchased autonomously by our users?’

We prefer simple rather than complex solutions.

We try to understand the technologies we use as much as we can. Finding the efficient solution is better long-term than just throwing money/machines at problems, and this is only possible if we know how things work underneath.

We’ll never invest 1$ to get $1.10. Finding and focusing on what has the highest ROI has been and will keep being essential to being a small team.

We’re fine with working remotely for months, but most of the year we work in the same office and for our stage this is very important, and we’d rather find someone that can be in the office with everyday. We have nice ocean views :)

How we got here - our story

Xoel started NoiceJobs in early 2020. It was a bunch of job boards for which he had to build a lot of job boards and a way to store those jobs.

TheirStack was born as a pivot from that in late 2021 to explore several hypotheses:

• jobs signal companies’ intents, problems and needs, and can be used as sales triggers
• jobs can also be used to infer the tech stack of companies

In 2023, Christian joined the team to amplify marketing and sales efforts, but thanks to his technical background he made lots of improvements in the backend, as well as all the work on the frontend both for our landing page and product.

And in 2024, we grew a lot, with double-digit growth in users and revenue every month.

Monthly active users in the last 6 months

What will you do?

We are looking for our first dedicated backend engineer to help scale and strengthen our platform. You don’t need to check every box below or use all the technologies we use, but what matters more is that you are excited to learn, adapt, and grow alongside our evolving company needs.

Your responsibilities

We have plenty of technical challenges that have to be solved to be confident we can keep growing at the same rate as in 2024 (6x revenue YoY)

Backend Development: API & Scraping

You will develop new API endpoints, update existing ones, and optimize them to improve scalability, performance, and reliability. Currently, our backend is a FastAPI app running on Render, but maybe we need to shift to deploying it with Kamal on Hetzher. You’ll know better than us and help us make these decisions, that you’ve made in the past already.

Scraping is at the core of our business - without it, we’d have no company. The scrapers we have need to be improved sometimes because we need to start scraping some attributes that we weren’t before, because the schema of the responses change (this is not very frequent) or we get blocked (not frequent either).

New scrapers will have to be developed as well to add new data sources and support our goal of covering 100% of job postings worldwide.

We run scrapers periodically with scheduled commands on Heroku. They sometimes fail and could have better visibility and monitoring to reduce this. Maybe we need to run them somewhere else and monitor them differently. You’d be the one in command of helping us find what’s best.

Performance Optimization & Data

The speed and performance of our APIs is key. This is because are we’re trying to become a really good data provider for other B2B SaaS products that resell our data and combine it with other kinds of data.

This is one of the reasons we’re migrating our main read database that processes all the searches from Postgres to ClickHouse. So you’ll need to be able to understand why a query is slow, get the SQL that is generated by that query, run EXPLAIN on it and be able to interpret it.

Maybe the schema will need to be changed, some indices have to be added, we need to add caching with tools like Redis or we need to add rate-limiting to some endpoints. You should be able to come up with potential solutions, balance the pros and cons or implement them.

You don’t necessarily need to have worked with Postgres or ClickHouse, but it would be great that you:

• have at least some experience with relational databases
• schema migrations (we use Alembic) and data migrations
• and have some intuition on why, given that the bulk of our performance problems come from job and company searches, we’re migrating to a columnar database instead of MongoDB, for instance.

DevOps: Optimizing, Monitoring & Reliability

You will play a key role in ensuring the stability and efficiency of our platform by enhancing CI/CD pipelines, reducing build times, and streamlining deployment workflows.

We serve over 2 million requests per day and while we already use Grafana and Sentry to monitor some things, our monitoring could be improved a lot. You’ll improve it to log failed requests and be able to attribute from which user they came, track system health, and identify backend issues such as memory leaks or unexpected restarts.

You’ll also improve how we monitor performance metrics (like P90, P95, P99 response times) and implement effective alerting mechanisms to ensure rapid resolution of issues. We use Slack

About you

You are a curious person and can learn things on your own.

You have experience building production-ready backend systems from scratch.

You’re familiar with testing, value code quality and maintainability.

You are a team player, like teaching what you know and helping others grow as well.

Ideally, you don’t have to be managed and can think of the right tradeoffs to be made to find the right technical solutions given the business context.

You don’t need to be fluent in English, but should be able to read and write in English, as most of our customers are international.

How we work

We normally work about 8h every day, and half days on Fridays. Normally starting at around 9, but very flexible on that, whether if it’s to start earlier and finish earlier or doing the same later.

We usually have a daily to sync on what we’re going to work on during the day, but most of the days we already know what’s important and what we need to do.

We’re big fans of the Getting Real and Let my people go surfing philosophies, we practice what we preach, and we think it’s compatible with hard work.

We use AI tools like Cursor every day and leveraging them it’s one of the things that let us go so fast this year. Not only we’re fine with you using them as well, we’d love if you’re already very familiar with AI tools and show us things we didn’t know yet that let us go even faster.

The team

As the first employee at TheirStack, you’ll work closely with the founders, helping to shape the company’s future:

• Xoel Lopez: Previously at Zara.com, Narrativa, and Tinybird, Xoel specializes in data and web scraping. He kickstarted TheirStack by developing the MVP and building the core data infrastructure, the scrapers and the API, from the ground up.
• Christian Palou: Previously at Manomano.com and Zara.com, Christian focuses on UX, front-end and backend development at TheirStack. Before TheirStack, he launched TrainerStudio.io, a SaaS for personal trainers that was acquired last year.

Compensation

Salary: 40-50k€ base + profit sharing.

We want the profit sharing part to be very big. We want incentives to be as aligned as possible and if we make a lot more, you make a lot more as well.

Equity can also be considered for the right candidate.

Location

A Coruña

Interview process

• One 30-min chat with us to get to know you, tell you a bit more about us and the position.
• A 30-min chat to learn more about your soft skills and your technical experience.
• A take-home test to spend 3-4h on. You can use AI on it, we care more about how you think and what production-ready means for you.
• Another 30-min short call to discuss the test.

One more thing

We’re flexible about many things (salary, profit share, location), and everything is pretty much negotiable. Nothing is written in stone.

Even if you don’t tick all boxes but still think this is an interesting position, are excited about the challenges we have and think you can help us make the pie larger, apply!

How to apply

Apply through this link