Principal Engineer

Lorien; Greater London; On-site; GBP 70,000 - 90,000; Full time

Job summary

A leading technology services firm is seeking a Principal Engineer for a 6-month contract in London, specializing in CDN migration. This role requires deep experience with CDN platforms, proven abilities in transitioning live traffic, and strong technical leadership to ensure effective and reliable implementation. The ideal candidate will work closely with internal teams to enhance system performance and risk management during this critical migration period. Excellent communication skills are essential for working with stakeholders at all levels.

Qualifications

• Deep, hands-on experience operating CDN platforms in production at scale.
• Proven experience transitioning or stabilizing live traffic between CDN platforms.
• Strong understanding of HTTP caching and TLS.

Responsibilities

• Lead technical authority for the CDN migration workstream.
• Ensure safe delivery of migration and meet performance expectations.
• Manage technical risk and guide transition to production traffic.

Skills

Operating CDN platforms in production at scale

Transitioning or stabilizing live traffic between CDN platforms

Understanding of HTTP caching

Understanding of TLS

Experience in failure modes

Working in high uptime environments

Ownership of existing platforms

Strong collaboration with teams

Communication skills

Job description

Job Title:Principal Engineer- CDN transition
Job location: London
Duration:6 Months
Description:

• The Contract Principal Engineer - CDN Migration is the lead technical authority for the CDN workstream within an active programme to migrate from an existing CDN platform to a target CDN.
• The role is responsible for technical leadership, decision-making, and hands-on delivery throughout the migration, including validating and refining the target solution, managing technical risk, and guiding the transition to full production traffic.
• This includes ensuring that traffic quality, bot management, and abuse controls are maintained or improved during the migration, particularly for media-style workloads with high visibility and sensitivity to false positives.
• Working closely with permanent engineers and programme stakeholders, the role ensures the migration is delivered safely, meets performance and reliability expectations, and leaves the organisation well-positioned to operate and evolve the new CDN platform.

Required experience & skills
Core experience

• Deep, hands-on experience operating CDN platforms in production at scale
• Proven experience transitioning or stabilising live traffic between CDN platforms
• Strong understanding of HTTP caching, TLS, edge routing, and failure modes
• Experience working in environments with demanding uptime and performance requirements
• Comfortable taking ownership of an existing platform and improving it pragmatically
• Strong collaborator who works effectively alongside permanent teams
• Calm, methodical approach to risk in high-change, high-traffic environments
• Strong communication skills with technical and non-technical stakeholders

Guidant, Carbon60, Lorien & SRG - The Impellam Group Portfolio are acting as an Employment Business in relation to this vacancy.