Senior Experience Platform Engineer – Frontend & AI

Callsign; Greater London; On-site; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Pension scheme with Scottish Widows

Private medical cover with Vitality

Life assurance (4x base salary)

Personal Learning & Development Budget

Cycle to Work Scheme

Company Family Leave

25 days annual leave plus CallsignBank

Employee Volunteering Program

Job summary

Callsign is seeking a product-focused engineer to own a client-facing surface such as the portal, demo and management platform. You will shape MVPs from briefs, define success metrics, and lead live adoption and performance goals.

You will set frontend standards, own end-to-end delivery, and drive AI-enabled workflows with a regulated verification discipline. Strong system design and cross‑team collaboration are essential.

Qualifications

• Must have solid JavaScript/TypeScript and React experience.
• Comfort beyond frontend: API, service, or infrastructure exposure.
• Experience in system design and architecture for cross‑domain features.
• Evidence of AI-native working with verification.
• Ability to design a test approach and defend it.

Responsibilities

• Ship across the stack: TypeScript/React frontends, Node services, API contracts, CI/CD pipelines and deployment tooling.
• Own testing strategy for a surface and drive release quality.
• Lead platform programmes including migrations, test-framework transitions and upgrades.
• Mentor junior team members and translate roadmaps into executable epics.
• Learn domain concepts like fraud, identity and client operations.

Skills

JavaScript/TypeScript

React

API/Backend exposure

System design

AI-native verification

Testing strategy

Product judgement

Frontend estate architecture

Tools

GitLab CI/CD

Terraform

Helm

GitOps

Job description

Callsign is seeking a product-focused engineer to own a client-facing surface such as the portal, demo and management platform. You will shape MVPs from briefs, define success metrics, and lead live adoption and performance goals.

You will set frontend standards, own end-to-end delivery, and drive AI-enabled workflows with a regulated verification discipline. Strong system design and cross‑team collaboration are essential.