Lead Full-Stack Engineer

Lead Full-Stack Engineer

New Delhi (On-site: Aerocity / Dwarka) · Full-time · 6+ years experience

About FlexiFone

FlexiFone is a UK-based multi-network mobile operator (MVNO). Our Multi-Network SIM and eSIM intelligently switch across the UK's major networks (EE, O2, Vodafone, Three) to give customers the best possible coverage, wherever they are.

We're a focused, fast-moving company building real telecom products — consumer apps, business connectivity, and IoT SIM solutions. Our team spans the UK and India, and we use the latest AI tools as a core part of how we build and ship.

The Role

We're looking for a Lead Full-Stack Engineer to take technical ownership of FlexiFone's entire product stack. This is a hands-on, build-first role — you'll be writing production code daily, making the architecture decisions, and driving how our platform is built.

You'll work closely with our Founder and Operations Manager, and collaborate directly with our Operations team to understand day-to-day challenges and turn them into the right technical solutions. As we grow, this role is positioned to expand into leading an engineering team.

You'll own and build across:

• Consumer Multi-Network SIM — web platform and mobile app
• Business & IoT SIM Dashboard
• Internal admin panels and operational tooling

What You'll Bring

Core stack:

• Backend: Node.js
• Databases: PostgreSQL (Supabase) and Firebase — bonus if you've migrated from Firestore to Postgres before
• Frontend (Web): Next.js
• Frontend (Mobile): FlutterFlow (Flutter)
• Platforms: Google Cloud, Vercel

Essential Knowledge:

• Fluency with modern AI coding tools — Claude Code, Codex, Cursor, etc. This is central to how we work, not a nice-to-have.
• Hands-on experience with payment processing (Stripe or similar)
• Hands-on experience using low-code, no-code automation and backend prototyping tools such as N8N, Make.com etc.

Engineering fundamentals for building a scalable product:

• Version control / Git, CI/CD:
• API design: Strong experience building and consuming REST APIs; clean, well-documented endpoints
• Databases at scale: Schema design, query optimisation, migrations, and data integrity
• Testing & quality: Writing tests and maintaining reliable, maintainable code
• Monitoring & observability: Logging, error tracking, and basic performance monitoring
• Cloud deployment: Comfortable deploying and managing apps on Google Cloud and Vercel

Nice to have:

• Basic understanding of the telecommunications and IoT space and eSIM technology — easy to pick up, but a head start is welcome.

Who You Are

• A genuine builder — you love shipping products end-to-end, not just reviewing other people's work
• Comfortable owning technical decisions and working autonomously
• Self-directed and pragmatic — you can take a problem from idea to production with minimal hand-holding
• A strong collaborator who enjoys working with non-technical colleagues to solve real operational problems
• Excited by the leverage that AI tooling gives a strong engineer
• Happy to work overlapping hours with the UK afternoon (roughly 12pm–8pm IST)

Why FlexiFone

• Solving real-world problems. Multi-network switching, IoT connectivity at scale, telecom billing, real-time dashboards.
• Modern, AI-forward workflow. No legacy bureaucracy — we build fast with the best tools available.
• Flexibility. Primarily on-site at our New Delhi workspace, with work-from-home permitted — we value in-person collaboration while trusting our team with genuine flexibility.
• Work alongside leadership. Direct collaboration with the Founder, Operations Manager, and wider team.
• Annual visits to our London HQ. Spend time with the wider team in the UK each year.
• UK relocation potential. For the right person, there's potential to relocate to the UK within the next couple of years.
• Competitive compensation for the right candidate, with room to grow into a leadership role as we scale.

Work Setup

This is primarily an on-site role based at our New Delhi workspace (Aerocity — WeWork, or Dwarka), with hybrid flexibility / work-from-home permitted.

How to Apply

Send your CV along with a short note about yourself and something you've built end-to-end, and which AI coding tools you use day-to-day to [email protected]

We move fast on strong candidates.

FlexiFone is an equal opportunity employer. We welcome applicants from all backgrounds.