At a Glance
- Tasks: Build and ship backend services in Python, powering AI features for investment firms.
- Company: Join a fast-moving alternative data platform with a small, dynamic engineering team.
- Benefits: Equity participation after six months, competitive salary, and a collaborative work environment.
- Other info: Mentorship opportunities and a chance to influence architecture decisions.
- Why this job: Shape the future of AI-driven analysis while working closely with founders.
- Qualifications: 5-15 years of backend experience in Python, with a focus on APIs and production environments.
The predicted salary is between 66150 - 80850 £ per year.
Join a team small enough that what you build is what exists, and take agentic AI features from a founder's idea to something hundreds of investment firms rely on to make real capital decisions.
What you'd actually work on:
- Building and shipping production backend services and APIs in Python (FastAPI) that power the platform's AI features, used daily by professional investors.
- Designing and owning the orchestration layer for agentic AI capabilities: how the system plans, calls tools, and retrieves the right data at the right time.
- Working directly with PostgreSQL and ClickHouse to enable fast, reliable data retrieval for AI-driven analysis at real scale.
- Taking a feature from a founder's rough idea to something live in production within the same sprint, without layers of process in between.
- Mentoring teammates and helping set engineering standards as the team grows from around seven engineers today to over thirty.
- Making real calls on architecture and tooling rather than inheriting decisions frozen in place years ago.
- Working closely enough with the founders that your technical judgment shapes what gets built next, not just how it gets built.
Where it gets technically interesting:
- Agentic workflows and tool use sit on top of a data platform that has to stay fast and correct under real investor usage, not a demo.
- Two different database workloads in the same system: PostgreSQL for transactional data, ClickHouse for the columnar, analytics-heavy queries behind the AI insights.
- AI coding tools (Cursor, Claude) are part of the actual day-to-day workflow, not a side experiment.
- A genuinely small engineering team means no one else is quietly maintaining the parts you don't touch.
- Retrieval and embeddings work that has to hold up against messy, high-stakes private market data rather than clean public datasets.
What we're looking for:
- 5 to 15 years of backend engineering experience, most of it in Python, in production environments.
- A track record of building and personally owning APIs or services used by real customers, not just maintaining systems someone else designed.
- Time spent at a startup or scaleup (roughly 30 to 100 people), not exclusively large corporate environments.
- Hands-on experience shipping AI or LLM features to production: agentic workflows, RAG, or tool use.
- Strong SQL and solid experience with PostgreSQL or an equivalent relational database.
- A genuine preference for staying hands-on and coding day to day rather than moving toward management.
- Based in Europe (outside France and the Nordics); if based in London, comfortable working from the office five days a week.
- Bonus: experience with columnar databases (ClickHouse, Redshift, Snowflake) or general DevOps/infrastructure skills.
The company:
An alternative data and private market intelligence platform, giving investors real-time data and AI-driven analysis to make faster, better-informed decisions. Used by hundreds of leading VC and PE firms across Europe and beyond. Small, fast-moving engineering team of around thirty people, still shaped day to day by its founders. Equity participation (ESOP) after six to nine months. Languages: English (fluent, working language of the team).
Senior Backend Engineer in London employer: The French Sourcer
As a Cloud Security Engineer at our regulated financial technology company in London, you'll thrive in a dynamic work culture that prioritises innovation while ensuring robust security measures. We offer competitive benefits including private health cover, pension contributions, and an equity plan, alongside flexible working arrangements that support your work-life balance. With a strong focus on employee growth, you'll have the opportunity to enhance your skills in a collaborative environment, tackling complex challenges in cloud security across multiple markets.
StudySmarter Expert Advice🤫
We think this is how you could land Senior Backend Engineer in London
✨Join Local Tech Meetups
Get out there and mingle with fellow developers by joining local tech meetups. It’s a fantastic way to meet people who might be working at The French Sourcer or know someone who does. Plus, you can pick up some trendy tech skills and trends while you're at it!
✨Contribute to Open Source Projects
Show off your coding chops by jumping into open-source projects. Not only does this give you practical experience, but it also gets you noticed in the dev community. You'll create a killer portfolio that speaks volumes about your skills to The French Sourcer.
✨Tap into Online Developer Communities
Don’t underestimate the power of online developer communities like GitHub, Stack Overflow, and even Reddit. Participate in discussions, share your projects, and build your visibility. We can often find opportunities through these channels that can lead to a full-time gig at companies like The French Sourcer.
✨Explore Job Boards Specifically for Tech Roles
Keep your eyes peeled on job boards that focus on tech roles. Sites like TechCareers or Stack Overflow Jobs can often have listings for companies like The French Sourcer that might not show up on broader job sites. Make it a habit to check these regularly, and don’t hesitate to apply directly through our website!
We think you need these skills to ace Senior Backend Engineer in London
Some tips for your application 🫡
Show off your coding skills:When applying for a software engineering role, it's super important to showcase your coding skills. Make sure your CV includes your tech stack, any relevant programming languages you’re comfortable with, and examples of projects you've worked on. If you have a GitHub profile, link it up! We love to see code in action.
Tailor your portfolio:For a full-time role, we’d expect to see some solid examples of your work in your portfolio. Make sure to include at least two or three projects that highlight your problem-solving skills and your ability to work with different technologies. Focus on the projects that are most relevant to the position at The French Sourcer.
Craft a killer cover letter:Your cover letter is your chance to stand out—make it personal! Explain why you want to work at The French Sourcer and how your skills align with the role. Show us your passion for software development. We dig enthusiastic candidates who understand the value of collaboration and continuous learning!
Be clear and concise:When it comes to writing your CV and cover letter, clarity is key. Avoid jargon that could confuse us and stick to simple, direct language. Highlight your achievements with quantifiable results where possible, and keep everything easy to read. A well-organised application goes a long way!
How to prepare for a job interview at The French Sourcer
✨Brush Up on Your Coding Skills
For a full-time software engineering role, it's crucial that we stay sharp with our coding abilities. Expect technical questions that might involve solving problems on the spot or discussing algorithms. Practise on platforms like LeetCode or HackerRank to get comfortable with the types of questions that often come up.
✨Know Your Tools and Frameworks
Make sure we’re well-acquainted with the tools and technologies listed in the job description. Familiarise ourselves with any specific frameworks or programming languages mentioned. If The French Sourcer uses React or Node.js, for instance, be ready to discuss how we’ve used them in previous projects or coursework.
✨Showcase Your Projects
Bring along a portfolio that highlights our best work. This could be code samples, GitHub repositories, or any side projects we’ve built. Make sure we can talk through our thought process for each project, especially the challenges we faced and how we solved them—this shows our problem-solving skills in action.
✨Prepare for Behavioural Questions
While technical skills are key, full-time positions also require cultural fit. Be ready to discuss our previous experiences and how we handle teamwork, conflict, and deadlines. Brush up on the STAR method—Situation, Task, Action, Result—to clearly articulate our past experiences when discussing how we've contributed to a team.
