Senior Full Stack Engineer – Typescript, C#, AWS, IAM, Security

Smart Sourcer; Remote; GBP 85,000 - 90,000; Full time

Job summary

A leading B2B SaaS company seeks a Senior Full Stack Engineer to develop APIs and enhance security features in a cutting-edge, AI-driven environment. The role requires strong skills in TypeScript, C#, and AWS, alongside a security-first mindset. This permanent position offers a competitive salary of £85k-£90k plus bonuses and benefits, with 95% remote work available. Join a dynamic team while making significant contributions to secure application development.

Benefits

Bonus

Benefits

95% Remote Work

Qualifications

• Strong full-stack development skills with TypeScript, C#, and AWS.
• In-depth understanding of security, Zero Trust, and OAuth2.
• Proven experience building RESTful APIs and secure coding practices.

Responsibilities

• Build full-stack APIs and integrations in TypeScript, C#, and AWS IAM.
• Deliver secure login, SSO, MFA, and tenant isolation at scale using AWS services.
• Collaborate with teams on embedding identity into features while upholding engineering excellence.

Skills

Full Stack Development

TypeScript

C#

AWS

Security Mindset

Job description

Senior Full Stack Engineer – Typescript, C#, AWS, IAM, Security

Outstanding opportunity to join this global B2B SaaS leader as a Senior Full Stack Engineer with some security and IAM exposure required to develop APIs to connect their IAM solution to their core applications. This permanent role offers the chance to shape how full stack applications embrace Zero Trust authentication and authorization services in a cutting-edge, AI-driven environment.

About the Role

• Build full-stack APIs and integrations in TypeScript, C#, AWS IAM
• Deliver secure login, SSO, MFA, RBAC / ABAC, and tenant isolation at scale, leveraging AWS services (Lambda, IAM, CloudFront, API Gateway, CDK)
• Collaborate across Product, Security, and Engineering teams, embed identity into new features, and uphold engineering excellence through CI / CD, testing, and incident response

Required experience

• Strong full-stack development skills (TypeScript, C#, AWS)
• An in-depth security mindset with an understanding of Zero Trust & OAuth2
• Proven experience with OIDC-compliant IDPs (Auth0, Okta, Cognito)
• Solid AWS expertise (IAM, Lambda, API Gateway, CDK)
• A proven background in building RESTful APIs that interact with IDPs
• Security-first mindset with experience in secure coding, threat modelling, and protecting PII
• Ability to mentor, collaborate, and lead with hands-on problem-solving

£85k-£90k + bonus + benefits. 95% remote & London