Senior Full Stack Lead Engineer

The ECA International Group

Greater London

Hybrid

GBP 90,000 - 120,000

Full time

2 days ago

Be an early applicant

Application generator

A complete application in a minute — tailored resume and cover letter, ready to send.

Get past ATS filters

Benefits offered by this job

Annual salary £90,000-£120,000

Enhanced Stakeholder Pension

25 days annual leave

Health, Life Insurance + EAP

Eligible for Annual Bonus Scheme

Long Service Awards

Cycle to Work Scheme

Flexible/hybrid Work Environment

Job summary

The ECA International Group is seeking a hands-on Full Stack Tech Lead to own core, multi-tenant SaaS foundations, mentor engineers, and shape architectural direction while remaining close to code.

You will work across identity, access, tenant isolation, and platform services, using Node.js, TypeScript/JavaScript, React, and AI‑first approaches to improve delivery. Lead Agile practices and drive impactful decisions.

Qualifications

8+ years of software engineering experience.
Hands-on with Node.js/React/TypeScript stack.
Experience building multi-tenant SaaS platforms.
Identity and access management experience (SSO/OIDC/SAML).

Responsibilities

Lead and mentor engineers while staying close to the code.
Own technical direction and set what good engineering looks like.
Architect scalable, maintainable multi-tenant solutions.
Collaborate with Product and Delivery to turn requirements into technical solutions.
Provide accurate estimates and drive delivery when blocked.

Skills

Node.js

TypeScript/JavaScript

React

SQL/NoSQL

CSS

Tools

AWS

PostgreSQL

GraphQL

Terraform

Playwright

C#/.NET Core

Job description

Want to lead technically without giving up the code?

We’re looking for a Full Stack Tech Lead to take ownership of some of the most important foundations behind ECA’s multi-tenant B2B SaaS platform.

This isn’t a role where “Technical Lead” means spending your week in meetings, updating spreadsheets and slowly drifting away from engineering.

You’ll still be hands‑on.

But you’ll also be the person helping set the technical direction, mentoring engineers, improving how we deliver software and tackling the difficult, cross‑platform problems that don’t fit neatly into one team.

And increasingly, you’ll help us answer another question:

What does a genuinely AI‑first engineering team look like?

What you’ll be getting stuck into

You’ll work across our shared platform foundations – the services and architecture that every product team relies on.

That includes areas such as identity and access management, roles and permissions, tenant isolation, integrations and scalable platform architecture.

You’ll be working primarily with Node.js, TypeScript/JavaScript and React, while helping us make good decisions about how our platform evolves.

You’ll also:

Lead and mentor engineers while remaining close to the code.
Own technical direction and help define what “good” engineering looks like.
Architect scalable, maintainable solutions for a multi-tenant SaaS environment.
Work closely with Product and Delivery to turn requirements into sensible technical solutions.
Give realistic estimates and challenge optimistic ones when needed.
Step into difficult or delayed projects, work out what’s blocking them and help get delivery moving again.
Lead Agile ways of working and encourage continuous improvement.
Help establish best practice around architecture, testing and TDD.
Use AI throughout the software development lifecycle – from design and build through to testing and review.
Explore how AI coding agents can genuinely improve engineering productivity, while putting the right guardrails around their use.

You’ll probably have 8+ years’ software engineering experience, but we’re more interested in what you’ve built, led and improved than simply counting years.

You’ll need strong hands‑on experience with:

Node.js
TypeScript / JavaScript
React
SQL / NoSQL
CSS

You’ll also understand what it takes to design and build scalable, multi‑tenant SaaS platforms.

Experience with identity and access management is particularly important – things like SSO, OIDC, SAML, authentication and authorisation, roles and permissions, tenant isolation and tools such as Keycloak.

Most importantly, we’re looking for someone who combines technical depth with leadership.

Someone who can make a difficult architectural decision, explain it clearly, help unblock an engineer and still roll their sleeves up when the situation calls for it.

The kind of Technical Lead who would rather unblock three engineers than be the hero on one ticket.

You’ll also need to be eligible to work in the UK.

Even better if…

You’ve worked with some of the following:

AWS
PostgreSQL
GraphQL
Terraform
Playwright
.NET Core or C#

And if you’re already experimenting with AI IDEs, coding agents or AI‑assisted software development, we definitely want to hear about it.

ECA is evolving its technology and products, and this role sits right in the middle of that journey.

You’ll have the opportunity to influence how we build, how we deliver and how we use AI within engineering, rather than simply inheriting a finished playbook.

So, if you’re a strong Full Stack engineer who enjoys leading people, solving difficult platform problems and still actually building things, this could be a very interesting next move.

You’ll also receive