Data Scientist Expert

Requirements

Must be eligible to work in Remote
Fluent proficiency in English (Written & Verbal)
Reliable high-speed internet connection
Bachelor's degree or equivalent professional experience
Demonstrated expertise in Software Engineering
How long hiring takes
Across the platforms we work with, people typically hear back about a hire within

about

30 days
of being referred.
Some are quicker, some take longer.
Within 2 weeks
~25%
Within 6 weeks
~60%
Within 3 months
~80%
Data Scientist Interview Prep
Practice questions for Data Scientist interviews in general. They are not taken from this listing, but they cover what interviewers in this field tend to ask.
How do you determine the required sample size for an experiment before running it?
I run a power analysis based on the minimum effect size that would actually matter for the business decision, the expected baseline variance, and the desired statistical power, typically 80%. Skipping this step is how teams end up running underpowered experiments that can't reliably detect real effects, then wrongly concluding a change had no impact.
What's the difference between correlation and causation, and how do you establish the latter with observational data?
Correlation just means two variables move together, which can be driven by a third confounding factor rather than either variable causing the other. With observational data, I look for natural experiments, instrumental variables, or matching techniques to approximate a controlled comparison, since a true randomized experiment usually isn't available and correlation alone can't support a causal claim.
How would you choose between a simpler statistical model and machine learning approach for a forecasting problem?
For data with clear seasonal and trend patterns and limited history, a statistical model like ARIMA or exponential smoothing is often more reliable than machine learning, which typically needs more data to outperform simpler methods. I'd benchmark both against a holdout period rather than assuming the more complex option is automatically better.
How do you handle a situation where your model's predictions need to be explained to justify individual decisions?
I'd use an inherently interpretable model where possible, or apply a post-hoc explanation method like SHAP values on top of a more complex model if the added performance is worth the extra explanation layer. The explanation needs to be accurate to how the model actually makes decisions, not just a plausible-sounding story layered on afterward.
See all 10 Data Scientist interview questions →
Why this role
This Data Scientist Expert role pays $75–$100/hr for your Software Engineering judgment directly, without requiring case files, client meetings, or firm overhead to get there.
Skills and categories
Explore other opportunities in related specializations:
Software Engineering
No Degree Required
Software Engineering & Coding
Data Science
STEM & Science
Expert
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Common questions
How and when does Ethos pay experts?
Within 30 days of invoice submission after a project closes. That net-30 schedule is standard for enterprise expert networks, but it's slower than the weekly payouts some AI training platforms offer, so plan your cash flow around it.
Is Ethos regular AI training work like rating chatbot responses?
No. Ethos is an expert network, not a task queue. AI labs, investment funds, and Fortune 500s pay to access your specific domain knowledge (deal analysis, clinical reasoning, legal logic, financial modeling) through three formats: multi-week consulting engagements, 30-60 minute advisory calls, and targeted research surveys.
What does task-based AI training work look like?
Practical, hands-on data work: recording short videos, categorizing images, rating text responses, or analyzing data. Tasks are designed to be short and distinct, typically 5 to 60 minutes each.
What does asynchronous AI training work mean in practice?
No set hours, no check-ins, no meetings. You log in when you want, pick up an available task, complete it, and submit; nobody is waiting on you in real time. That's different from remote employment, where you're expected online during business hours. The tradeoff: you're competing with others for available tasks, so an empty queue means there's simply nothing to do until more work is released.
What does Software Engineering work look like for a Data Scientist Expert?
Tasks here are scoped to Software Engineering, not generic labeling. As a Data Scientist Expert, expect to draw on real domain judgment (evaluating outputs, correcting errors, or providing expert reasoning specific to Software Engineering) rather than following a one-size-fits-all rubric. If you don't have hands-on Software Engineering background, this is likely not the right listing to start with.
What specific skills does this listing call for?
Expert is named directly in the listing. If you don't have hands-on experience with this, expect the screening process to test for it directly rather than accepting adjacent experience as a substitute.
How much does this specific role pay?
This listing is posted at $75–$100/hr, an hourly rate. The range reflects experience level and negotiated terms, not a placeholder, so where you land in it depends on your background and the assessment. Pay can change between when we last checked the listing and when you apply, so confirm the current number on the platform's own application page before committing time.
What happens when I click Apply on this listing?
You'll be taken to Ethos's external site to complete your application there. This listing links through a referral, but the process is identical to applying directly; the link just routes you correctly. Create an account on their site and follow their onboarding steps.
Who built Ethos and is it legitimate?
Yes, it's legitimate and well-funded: Ethos raised $3.5M from General Catalyst and was co-founded by Daniel Mankowitz (Google DeepMind research scientist and lead author of AlphaDev) and James Lo (McKinsey, SoftBank Vision Fund). Over 17,000 experts have signed up, and it's actively working with 25+ PE firms, hedge funds, and consultancies. The referral link on this page is an affiliate link; it doesn't affect your pay or opportunities.