Hiring teams often split these into separate problems: the technical interview tests technical skills, and a culture fit conversation tests "soft" skills. The separation sounds logical. It produces a category error.
Soft skills — how someone communicates under cognitive load, whether they update their approach when new constraints appear, how they respond to pushback on a technical decision — are best observed when technical complexity is present, not absent. A candidate who communicates well in a casual conversation but reverts to terse, defensive communication when debugging a system design problem has told you something important. But only if you were watching for it.
This guide covers what to assess, which methods produce valid signal, and how to score soft skills in a way that survives scrutiny.
Why Soft Skills Matter in Technical Roles
The conventional framing treats soft skills as secondary to technical skills for engineering roles. This framing fails at two points.
First, engineering work is not a solo activity. Writing code is; everything else — design reviews, sprint planning, incident response, cross-functional coordination, mentoring — requires communication and collaboration. A senior engineer who cannot explain a tradeoff clearly or engage with criticism constructively creates organizational debt that compounds over time.
Second, soft skills are the primary differentiator at senior levels. The difference in technical output between two senior engineers is typically marginal; the difference in organizational multiplier — how much they accelerate the people around them — is enormous. That multiplier is almost entirely made up of what we call soft skills.
For a complete view of how soft skills fit into a broader evaluation design, see the full technical skills assessment framework.
Which Soft Skills to Actually Assess
Not all soft skills are equally assessable in an interview setting. Some require months of context to evaluate accurately; others surface clearly in a 60-minute session. Prioritize what you can observe reliably.
| Soft Skill | Assessable in Interview? | Best Method |
|---|---|---|
| **Communication clarity** | Yes — strongly | Observation during technical work; ask them to explain a past decision |
| **Adaptability** | Yes | Change a constraint mid-problem; observe how they respond |
| **Constructive disagreement** | Yes | Push back on their approach; observe the response |
| **Self-directedness** | Moderate | Behavioral question + how they structure ambiguous problems |
| **Empathy and mentoring instinct** | Moderate | Behavioral questions about past team interactions |
| **Long-term reliability** | Low | Requires references and track record, not interview performance |
| **Cultural values fit** | Low-Moderate | Values-based questions, but high risk of performance vs. authentic signal |
Focus on the top four. These have the highest signal-to-noise ratio in a technical interview setting and the strongest correlation with on-the-job performance in engineering roles.
Methods That Produce Valid Signal
1. Structured Behavioral Questions (with Probing)
Behavioral questions — "Tell me about a time when..." — are the most common method and produce the most variable signal, ranging from highly predictive to useless, depending on execution.
The method works when:
- Questions are specific to engineering-relevant situations (not generic leadership scenarios)
- Interviewers probe the Action layer rather than accepting the narrative
- Responses are scored against a defined rubric, not impressionistic reactions
The method fails when:
- Candidates prepare polished stories that demonstrate surface behavioral awareness without underlying change
- Interviewers accept the Situation and Result as the complete answer
- Questions target values people already know are correct ("Tell me about a time you prioritized the team over yourself" selects for well-rehearsed answers, not genuine patterns)
2. Observation During Technical Work
The most underused method. When a candidate is working through a technical problem — a live coding interview or a pair programming session — every soft skill you care about has the opportunity to surface naturally.
Communication clarity: Are they explaining their reasoning as they go, or working in silence? Adaptability: When you change a constraint — "Actually, we can't use a database for this" — do they integrate it and adjust, or anchor to their original approach? Constructive disagreement: When you suggest an alternative approach, do they engage critically, accept without consideration, or dismiss without engagement? Self-directedness: When they hit an ambiguous point, do they ask clarifying questions and make a decision, or wait for direction?
These observations require a defined rubric prepared before the session. Without a rubric, the observation produces a general impression rather than scored data.
3. Work Sample Scenarios
For senior roles, code review scenarios are particularly strong for soft skills assessment. Provide a code sample with several issues of varying severity — some critical, some stylistic. Ask the candidate to review it as they would a junior engineer's PR.
What this surfaces: Communication style (are they direct but constructive, or dismissive?), prioritization ability (do they distinguish critical issues from nitpicks?), teaching instinct (do they explain why something is a problem, or just flag it?).
The scenario is realistic — it is literally what senior engineers do — which removes the performance dynamic from behavioral questions.
Structured Behavioral Questions: The Right Way to Use Them
Behavioral questions structured around STAR (Situation, Task, Action, Result) are the standard framework. The framework works; the execution typically does not.
The most common failure mode: Interviewers accept a 2-minute narrative as the complete answer. The narrative describes Situation and Result with a brief mention of Action. The interviewer moves on.
The fix: The value is in the Action layer. Probe it every time.
After a candidate describes a situation, follow with:
- "Walk me through specifically what you did next."
- "You mentioned you resolved the disagreement — how did that conversation actually go?"
- "What did you do differently in the moment vs. what you wish you had done?"
The final probe — "What would you do differently?" — is the highest signal question in behavioral interviewing. It distinguishes candidates with genuine self-awareness from candidates with polished retrospective narratives. A candidate who says "honestly, I would have pushed back earlier on the timeline and accepted the discomfort of that conversation" has told you something real. A candidate who says "I would have communicated more proactively" has told you nothing.
Recommended behavioral questions for engineering roles:
- "Tell me about a technical decision you made that you later realized was wrong. How did you handle it?"
- "Describe a situation where you disagreed with a technical direction chosen by a more senior person. What did you do?"
- "Tell me about a time you had to explain a complex technical problem to a non-technical stakeholder. How did you approach it?"
- "Describe a situation where you had to change your approach significantly mid-project because new information emerged."
For each question, probe the Action. Score against the rubric immediately after the session.
Observing Soft Skills During Technical Rounds
Define observation criteria before the session begins. The rubric categories to track during a technical interview:
Communication under cognitive load
- Does the candidate explain their reasoning as they work, or only when asked?
- Can they articulate a tradeoff clearly: "I'm choosing X over Y because..."?
- Do their explanations adjust appropriately for what you already know?
Adaptability
- When constraints change, how quickly do they integrate the change vs. anchor to prior assumptions?
- Do they ask clarifying questions to understand the new constraint, or proceed without checking?
Receptiveness to feedback
- When you suggest an alternative: do they engage analytically ("That's interesting, the downside is..."), accept without consideration ("Sure, I'll do that"), or dismiss ("I don't think that's the right approach") ?
- Do they update their approach when feedback is technically valid?
Handling ambiguity
- When the problem has an unclear aspect, do they ask a targeted question and proceed, or wait for complete specification before starting?
- Do they make their assumptions explicit?
Use a 1-4 scale for each. Score immediately after the session — these nuances fade within hours.
Scoring Soft Skills Consistently
The objection to soft skills scoring is that it is subjective. It is — unless you define behavioral anchors before the interview.
Example rubric: Constructive Disagreement
| Score | Behavioral Anchor |
|---|---|
| **4** | Challenged an approach, provided specific reasoning, proposed an alternative, and remained open to counter-argument. Discussion moved toward a better outcome. |
| **3** | Challenged an approach with reasoning. Did not volunteer an alternative but engaged constructively with discussion. |
| **2** | Expressed disagreement without supporting reasoning, OR accepted all suggestions without engaging critically. |
| **1** | Did not express any disagreement (even when the interviewer's suggestion was clearly suboptimal), OR became defensive/dismissive when challenged. |
Example rubric: Communication Clarity
| Score | Behavioral Anchor |
|---|---|
| **4** | Consistently explained reasoning unprompted. Adjusted explanation depth based on context. Could articulate tradeoffs clearly. |
| **3** | Explained reasoning when prompted. Generally clear but required follow-up questions to surface key decisions. |
| **2** | Communicated outputs but not reasoning. Required frequent prompting to explain approach. |
| **1** | Primarily silent during technical work. Could not clearly explain decisions when directly asked. |
Write your behavioral anchors before the session. Use the same rubric across all candidates for the same role. Discrepancies between interviewers become visible and reviewable rather than hidden in vague impressions.
How Nextmantra AI Evaluates Soft Skills
Nextmantra AI conducts first-round 45-minute voice interviews and scores candidates across both technical depth and soft skills dimensions. The AI evaluates communication quality throughout the session — not as a separate assessment, but as an observable layer on top of the technical conversation. The evaluation report surfaces: how clearly the candidate explained their reasoning, whether they asked clarifying questions when constraints were ambiguous, how they responded when the AI challenged a claim or provided alternative framing, and whether their communication style adapted as question complexity increased.
This means your team receives soft skills signal on first-round candidates before a single engineer has spent time on the process. The candidates who reach behavioral and pair programming interviews have already been evaluated on baseline communication and adaptability. See how Nextmantra AI structures its evaluation criteria
Frequently Asked Questions
Can you actually assess soft skills in a technical interview?
Yes — but only if you design the session to surface them. Structured behavioral questions with probing, and deliberate observation of communication during technical work, both produce valid signal. The key is defining rubric criteria before the session, not relying on impressions after.
Which soft skills are most important for software engineers?
For software engineering, the highest-impact soft skills are communication clarity, adaptability, constructive disagreement, and self-directedness. These compound over time and most strongly predict performance in senior and lead roles.
What is the STAR method and does it work for technical soft skills?
STAR (Situation, Task, Action, Result) works when interviewers probe the Action layer rather than accepting the full narrative at face value. The most important follow-up question: "What would you do differently?" This distinguishes genuine self-awareness from polished retrospective storytelling.
How do you score soft skills without being subjective?
Define observable behavioral anchors for each score level before the interview. When scores are anchored to specific behaviors rather than impressions, inter-rater reliability improves and the subjectivity argument loses most of its force.
Should soft skills be assessed in a separate interview or during the technical round?
Both. The technical round surfaces soft skills under realistic cognitive load — more representative than a relaxed behavioral conversation. A separate behavioral interview allows deeper exploration of specific incidents. Running both produces more signal than either alone.
Conclusion
Soft skills are not a separate category from technical skills — they are the layer that determines whether technical skills create organizational value or remain individual throughput. The engineers who scale a company's output 10x versus 2x are almost always differentiated by soft skills, not technical depth.
Assessing them requires structure: define what you are measuring, choose methods that surface those skills under realistic conditions, write behavioral anchors before interviews start, and score immediately afterward. The investment is modest compared to the cost of a miscalibrated senior engineering hire.
Need AI-assisted first-round screening that evaluates communication alongside technical depth? [See how Nextmantra AI works](https://nextmantra.ai/platform)
Sources: SHRM (2023). Critical Soft Skills for Engineering Teams. Google Re:Work (2019). What Makes a Google Team Effective. LinkedIn Global Talent Trends (2022). Soft Skills in Technical Hiring.