Senior Machine Learning Engineer (AI Decisioning)

Before jumping into all the information about the role and what you can bring to the table, let us introduce ourselves real quick.
About us
Insider One is the #1 platform that brings everything marketing and customer engagement teams need in one place so they can reach their peak potential and become unstoppable.
Our story began with six desks and a vision to create a single platform to make industry-first technologies and emerging channels accessible to marketers worldwide. Today, Insider One is powered by 1,500+ team members representing 50+ nationalities across 30+ offices. With AI at its core and an integrated Customer Data Platform (CDP), Insider One unites data, personalization, and journey orchestration across the most extensive set of natively supported channels, including WhatsApp, SMS, Email, Web, App, and Site Search.
We recently raised one of the largest funding rounds in the industry, a $500M Series E led by General Atlantic. We are backed by top-notch investors, including Sequoia Capital, QIA, Riverwood, and Endeavor Catalyst, and trusted by 2000+ customers from high-growth startups to the most prestigious Fortune 500 companies such as Samsung, Nike, L’Oreal, Singapore Airlines, Nestlé, Nissan, Lenovo, Puma, IKEA, Allianz, Domino's, and the list goes on.
Insider One was congratulated for becoming one of the only woman-founded, women-led B2B SaaS unicorns in the world. Loved by customers, recognized by analysts, we are the only vendor recognized as the #1 leader in all the capabilities marketing and customer engagement teams need. Don’t just take our word for it — see for yourself. We consistently outperform and continue our leadership, andthe results speak for themselves.
From day one, Insider One’s mission has not only been to build a world-class product company, but also to create one of the most socially progressive technology communities in the world. Through our social responsibility initiatives like 100 Social Responsibility Projects, AI Training for Teachers, Code Academy, SheCodes, SheLeads, and SheMarkables, our community has committed to scaling its impact on our communities across 30+ countries, driving initiatives in health, education, farming, animal rights, and increasing women’s representation in STEM.
Behind all these achievements is an exceptionally talented, visionary team of overachievers that moves fast and agile, creating cutting-edge products, and focuses on making an impact. If you want to be a part of this journey, just keep reading.

We are looking for a Senior Machine Learning Engineer who wants to take their career one step further by working on one of the most consequential AI surfaces at Insider One, the engine that powers personalized experiences in real time. If you are drawn to problems like online decision-making under uncertainty, sequential recommendation, joint optimization across competing objectives, read on.

At Insider One, we work on the hard problems behind making customer engagement feel personal at scale — where machine learning meets a real user, in real time, across every channel they use.

We believe in M-shaped development culture: engineers with depth in few core areas and curiosity to expand across the stack. You’ll collaborate with different functions and be hands-on across the full stack: from data and modeling to software systems and observability. You’ll grow quickly, owning meaningful pieces of the products with ultimate support from experienced engineers and scientists around you.
What You Will Do

Design, build and release real-time decisioning systems that learn from interaction feedback at scale.

Own the modeling logic from how we represent users and signals to how reward attribution closes the loop and improves the next interaction.

Move ideas from papers and notebook prototypes including online learning policies and counterfactual estimators to production code that runs behind real-time APIs.

Design and build resilient streaming/batch pipelines that feed user state, reward signals, and offline replay.

Run honest experiments, A/B test what you ship, design offline evaluation for what you cannot, and kill your own work. when it doesn’t outperform against the baseline.

Continuously monitor and improve the quality, latency, observability, and scalability of the systems.

Collaborate across platform and product teams to turn research-grade ideas into production-grade products.

Share context, mentor engineers, raise the technical bar of the team, and help set direction for how we do ML at scale.

What You Will Need

You don’t need to tick every box

if you likely have:

Designed and deployed personalization, ranking, or recommendation systems used by real users; improved core engagement metrics (CTR, conversion, retention, revenue) and can talk concretely about the lift

Familiarity with sequential recommendation, ranking, or joint / multi-objective optimization problems where you can't optimize one metric without trading off another

A/B tested the impact you’ve provided and iterated based on what the data said

Comfortable with the messy reality of production ML: cold start, sparse signal, label delay, feedback loops, distribution shift

Solid grounding in probabilistic modelling (Bayesian inference, calibration, hierarchical models) and modern recommender techniques (embeddings, sequence models, LLM-driven content understanding), applied to sequential, ranking, or multi-objective problems

Software engineering, production-quality code and at least one programming language, care about API contracts, testing, and observability, not just notebooks

Built high-throughput real-time or batch pipelines supporting ML training and inference, on AWS (or an equivalent major cloud) comfortable owning a service end to end across compute, storage, networking, and CI/CD

Have moved at least one model from a paper, a notebook, or a whiteboard sketch into a real system that serves traffic, and can speak honestly about what broke along the way

and it would be a strong plus if you have any of below:

Hands-on experience with online decision-making under uncertainty, multi-armed bandits, contextual bandits, Thompson sampling, UCB, or RL agents that have served traffic

Comfortable reasoning about exploration vs exploitation, regret, off-policy evaluation (IPS, doubly robust), counterfactual estimation, and the failure modes of each

Causal inference / uplift modeling

Academic research experience or publications in online decision-making under uncertainty, reinforcement learning, sequential recommendation, optimization, or related fields.

What We Offer

Curiosity and initiative you love to figure things out and solve complex problems.

Collaborative ownership and team/product-first approach.

Breadth and depth you’re excited to grow into M-shaped product engineer.

Self-organization and full ownership through real-world impact.

A strong team that ships and learns together.

Continuous mentorship and technical coaching.

Enjoy a monthly meal allowance designed to enhance your daily routine.

Access comprehensive private health insurance.

Feed your curiosity with access to Spotify, LinkedIn Learning, Blinkist, MasterClass, Neoskola, and CloudGuru.

Level up with internal trainings covering AI fundamentals, coding, foreign languages, and a wide range of personal development skills.

Be part of a diverse team that’s as global as it gets, where every voice is heard and 50+ nationalities build together.

Become a Shareowner through our eligibility-based “ESOP” and own a piece of what you build.

Help build the team you want to work with and enjoy rewarding referral bonuses.

Opportunities to give back to your community through volunteering and purpose-driven social impact projects.

From global retreats to team-building activities, expect year-round events that turn into lifelong memories.

Get inspired by the greatest minds in the tech industry through events like our Tech & Dev Talks.

Work from anywhere in Turkey through our fully remote setup.

We aren't just hiring for a position; we are hiring for a mission — a mission to build a lasting legacy that will set the benchmark for the most progressive tech companies out there. To do this, we are looking for exceptional talent to join a community of good-hearted individuals who take high ownership and are relentlessly driven to go the extra mile. If this sounds like who you are and where you aspire to be, we are excited to meet you.
We provide equal opportunity in a zero-discrimination workplace and not just welcome but also embrace everyone without regard to sex, race, color, nationality, religion, gender identity, sexual orientation, disability status, citizenship, or marital status.
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