Senior Software Engineer

Job description

Senior Front Office Software Engineer – Real‑Time Trading Systems

Contract – Inside IR35

£700 - £1100 per day

London – Hybrid (3 days in office)

The Short Version.

You must be a senior software engineer with experience in trading environments.

You need to be a well-rounded engineer in Python, C# / .NET or other object-oriented languages. With an ability to deliver real-time cloud based solutions at the speed a trading desk needs.

Want to know more? Click to apply or read the full JD below.

Full Job Description:

You’ll be joining a global energy trading environment, building real‑time systems and Front Office tooling that directly support gas and power traders. This is a hands‑on engineering role in a fast‑moving setting where delivery cycles are measured in hours and days, not weeks.

Working across UK and Denmark engineering teams, you’ll take ownership of critical trading systems, help shape architectural direction, and deliver high‑impact software that underpins pre‑trade decision‑making.

What You’ll Do

• Build, enhance and support real‑time trading systems across gas and power markets
• Own delivery end‑to‑end: design, build, test, deploy and iterate
• Partner closely with traders, analysts and quants to refine rapidly evolving requirements
• Contribute to strategic rebuild efforts, including a long‑term shift towards C#
• Improve ingestion, validation and analytics tooling across Front Office platforms
• Shape architecture and steer the technical direction of key systems
• Collaborate with a mixed London/Denmark engineering team in a highly business‑facing environment

Tech Stack

Languages:

• C# / .NET (strategic direction)
• Python (current tooling base)
• Java or other OO languages also considered

Cloud:

• AWS (current environment)

Frontend:

• Angular
• Svelte
• React experience also relevant

Data / Messaging:

• Strong database fundamentals (Postgres, ClickHouse or equivalent)
• Kafka or similar real‑time messaging technologies

What We’re Looking For

• Strong software engineering experience in Front Office or real‑time trading environments
• Proven ability to build and support low‑latency or event‑driven systems
• Comfortable working directly with demanding trading stakeholders
• Broad engineering skillset — backend first, with UI capability where needed
• Ability to operate in a hybrid Python/C# world and contribute to long‑term technical evolution
• Architectural awareness and ability to shape platform design
• Gas/Power trading experience preferred — otherwise must speak confidently about the markets they've supported

This is not a data engineering role — it’s a business‑focused, full‑stack/trading systems engineering position suited to someone who thrives in real‑time, high‑ownership environments.

Team & Culture

• London team of 8 engineers (mix of backend, infra and support)
• European team of 5 engineers working closely with London
• Highly collaborative, business‑facing, delivery‑focused engineering culture
• Fast iterations, high visibility, and systems used directly on the trading floor

Apply Now

Click the link provided

OR

Email: Barry.Ansell@Harringtonstarr.com

Extra information

Status

Open

Education Level

Secondary School

Location

City of London

Type of Contract

Full-time jobs

Published at

08-03-2026

Full UK/EU driving license preferred

No

Car Preferred

No

Must be eligible to work in the EU

No

Cover Letter Required

No

Languages

English