Lead / Principal Engineer - Full Stack

Sahaj Software; Greater London; On-site; GBP 120,000 - 180,000; Full time

Benefits offered by this job

Unlimited leave

Life & private health insurance

No hierarchy

Open Salaries

Job summary

Sahaj Software is seeking a Principal Consultant to partner with customers, frame business problems and drive technical direction. You’ll lead architecture discussions, contribute hands-on delivery, and mentor teams across distributed systems at scale.

Join self-managing, high-impact teams shaping strategic technology decisions. You will collaborate with leadership, manage stakeholders, and translate business goals into robust engineering solutions while maintaining focus on scalable, secure

Qualifications

• Demonstrated ability to build software systems in complex environments.
• Strong fundamentals and expertise in at least one programming language.
• Hands-on experience delivering distributed systems at scale.
• Deep understanding of architecture, trade-offs, and system design.
• Experience working with customers and business stakeholders.

Responsibilities

• Frame problems with customers and propose technical solutions.
• Lead architecture reviews and technical workshops.
• Contribute hands-on to design, implementation and code reviews.
• Mentor practitioners and guide teams through complex decisions.
• Influence product and technology direction with stakeholders.

Skills

Distributed systems

Architecture & design

Customer engagement

Hands-on delivery

Polyglot language skills

Engineering leadership

Job description

A different kind of organisation

• High trust, transparency, and autonomy
• Small teams, high ownership, flat structures
• Radical compensation transparency
• Sense of ownership in collective success
• Work with exceptional people who deeply care about their craft

The role

As a Principal Consultant, you’re often the first person a customer meets to brainstorm a business problem. You should be at home debating distributed systems with engineers and framing decisions with leadership. You’ll frame the problem with customers, shape the approach with the team, provide technical direction, and stay hands-on through delivery. You will work in self-managing, experienced, small, and high-impact teams, solving hard problems. This is a consulting & tech delivery role and while you will not have direct reports, you will regularly influence teams, mentor practitioners, manage stakeholders, and guide organisations through complex technology and business decisions.

What the work looks like

We can’t promise which problem you’ll pick up, but the menu right now looks something like this:

• Redesign a ClickHouse schema so an ad buyer can query 85 billion rows in under two seconds, and discover that pre-exploding the rows 168x is actually the right answer.
• Keep a vehicle telemetry platform moving billions of messages a day without the Kafka consumers falling over.
• Build the engineering spine of a mobile wallet used by more than two billion people across four continents.
• Ship the data product behind peer-review submissions for one of the world’s largest scientific publishers.

The list changes every quarter. The pattern doesn’t: data-heavy, distributed, and often sitting on top of something that already exists and isn’t perfect.

What you’ll do

Frame Problems & Propose Solutions

• Help customers find the right problem before jumping to a solution.
• Facilitate discovery sessions, architecture reviews, and technical workshops.
• Translate business goals into a technology strategy and an execution plan.

Lead Through Technical Excellence

• Stay hands-on; contribute directly to design, architecture, implementation, and review.
• Make pragmatic calls balancing business needs, engineering quality, and delivery timelines.
• Guide teams to build scalable, resilient, secure systems and the practices that keep them that way.

Influence, Advise, and align

• Act as a trusted advisor on technology and investment decisions; assessments, due diligence, advisory.
• Build trust and alignment across Sahaj and customer teams
• Converge competing priorities into a path forward.
• Communicate complex ideas clearly to technical and non-technical audiences.
• Shape new work through discovery and proposals; mentor others and raise the bar as you go.

Operate Across Technology Domains

Distributed systems, data engineering, AI & agentic systems, DevOps/SRE. Depth in few areas; breadth across, and appreciation for trade-offs in context.

You’ll thrive here if

• You reach for the simplest solution that gets the job done and distrust accidental complexity.
• You think in systems, not isolated parts.
• You stay calm when the path is unclear and build clarity for those around you.
• You move easily between the org-level picture and the technical detail.
• You’re curious by default and pick up new domains fast.
• You’d rather be in the room with a customer solving a real problem.

What we’re looking for

• Demonstrable building software systems in complex environments.
• Strong engineering fundamentals; expert in at least one language, ideally polyglot.
• Hands‑on experience designing and delivering distributed systems at scale.
• Deep grasp of architecture, system design, and engineering trade-offs.
• Direct experience working with customers and business stakeholders.

What will you experience in terms of culture at Sahaj?

• A culture of trust, respect and transparency
• Opportunity to collaborate with some of the finest minds in the industry
• Work across multiple domains

What are the benefits of being at Sahaj?

• Unlimited leaves
• Life insurance & private health insurance
• No hierarchy
• Open Salaries