Senior Software Engineer – AI & Prompt Engineering - £100k - Python/ TypeScript

La Fosse; England; Hybrid; GBP 60,000 - 80,000; Full time

Benefits offered by this job

Impactful work

Career growth opportunities

Collaborative culture

Tech-first environment

Flexibility in work model

Job summary

An innovative AI software company in London is seeking a Senior Software Engineer to develop scalable AI-driven applications. This role involves working closely with AI specialists, designing APIs, and mentoring junior engineers. The ideal candidate has extensive experience in Python and TypeScript, hands-on knowledge of LLMs, and is comfortable in a dynamic startup environment. The company offers a hybrid working model and fosters a collaborative culture that encourages impact-driven work.

Qualifications

• Strong experience with Python and TypeScript.
• Hands-on expertise with LLMs (OpenAI, Hugging Face, or similar).
• Proven ability to design scalable systems and mentor others.
• Passion for AI and curiosity about prompt engineering.
• Comfortable in a growing, startup-style environment.

Responsibilities

• Develop and maintain systems using Python and TypeScript.
• Collaborate on prompt engineering and model fine-tuning.
• Design APIs and user-facing features for AI-powered products.
• Contribute to technical strategy and mentor junior engineers.

Skills

Python

TypeScript

Prompt engineering

LLMs expertise

Mentoring

Job description

This range is provided by La Fosse. Your actual pay will be based on your skills and experience — talk with your recruiter to learn more.

Base pay range

Direct message the job poster from La Fosse

Head of Practice - Software Engineering @ La Fosse

I’m working with an exciting AI software company based in London that’s at the forefront of prompt engineering and Large Language Model (LLM) innovation. They’re building cutting‑edge solutions that redefine how businesses interact with AI, and they’re scaling quickly.

The team currently sits at around 20 people, and they’re looking for a Senior Software Engineer to join them as they grow. This is a fantastic opportunity to work in a collaborative, tech‑first environment where your ideas will have a direct impact on next‑generation AI products.

As a Senior Software Engineer, you’ll play a key role in designing and building scalable AI‑driven applications. You’ll work closely with AI specialists and product teams to integrate LLMs, optimise prompts, and deliver robust solutions.

Key Responsibilities

• Develop and maintain systems using Python and TypeScript.
• Collaborate on prompt engineering and model fine‑tuning.
• Design APIs and user‑facing features for AI‑powered products.
• Contribute to technical strategy and mentor junior engineers.

What They Offer

• Impactful Work: Your contributions will shape next‑gen AI products.
• Career Growth: Opportunities to lead projects and specialise in cutting‑edge AI.
• Collaborative Culture: Flat structure, open communication, and a strong learning ethos.
• Tech‑First Environment: Modern stack, cloud‑native infrastructure, and continuous innovation.
• Flexibility: Hybrid working model with a vibrant London office.

Ideal Candidate

• Strong experience with Python and TypeScript.
• Hands‑on expertise with LLMs (OpenAI, Hugging Face, or similar).
• Proven ability to design scalable systems and mentor others.
• Passion for AI and curiosity about prompt engineering.
• Comfortable in a growing, startup‑style environment.

Seniority level

Mid‑Senior level

Employment type

Full‑time

Job function

Information Technology

Industries

Software Development

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